At the present time, it is common to use image forming devices having document reading functions such as copiers, fax machines and scanners, which are provided with document transport devices. Document transport devices comprise a multiplicity of rollers on a document transport path, and because the document transport path turns, the internal mechanisms are complex and a the documents can be in various types of paper and various formats, documents sometimes jam in the internal document transport path. At this point, in order to remove the jammed document, it is necessary to expose the document transport path within the document transport device.
Furthermore, in the case of copiers capable of reading both sides of the document at the same time, a document reading area is also provided within the document transport device, and it is also necessary to expose the interior of the document transport device in order to clean that document reading area.
In terms of means for exposing the document transport path, means have been proposed wherein an external cover is opened to expose the interior from the top, and those wherein the document transport device (automatic document transport device) is opened with respect to the transparent glass platen (contact glass) so as to expose the pressure plate on the bottom thereof, whereafter an auxiliary frame is swung open from the top, so as to expose the document transport path from the underside thereof.
Furthermore, conventionally, devices have been proposed wherein the document transport device is opened with respect to the transparent glass platen (glass plate) and a bottom auxiliary frame is opened to expose the document transport path.
Furthermore, a plastic pressure sheet, which is backed with a soft material such as sponge, is generally mounted on the underside of the document transport device, so that the document that is placed on the transparent glass platen lies closely against the platen.
However, in the first mentioned prior art, it is not possible to expose the document transport path without first removing the external cover, which is bothersome and requires that a space be available in which the external cover that has been removed can be placed.
Furthermore, in the second mentioned prior art, with devices wherein a bottom auxiliary frame is opened to expose the document transport path, if the pressure sheet (document hold-down plate) is made from a soft material, the pressure sheet is bent, and this bending crease may result in the document not being sufficiently pressed against the transparent glass platen, so that the document cannot be read properly.
Thus, an object of the present invention is to provide an image forming device wherein the document transport device used in the image forming device allows for exposure of the interior of the document transport device from the bottom by a single operation, and wherein the pressure sheet is not bent when the interior of the document transport device is exposed.